The invention generally relates to gas burner devices used in home and commercial range-top stove applications. More particularly, the invention relates to burners in which the fuel and air are swirled and the flames converge towards a heat concentration point to provide improved heating of a cooking vessel.
Traditional gas burners for cook tops and stoves are so-called “external flame” gas burners in which the flames extend radially outwards from the burner during operation. These burners provide satisfactory performance, and typically provide a heat transfer efficiency of about 30-40% to a cooking vessel resting on a grate over the burner.
One of the techniques used to provide more efficient combustion is to cause the fuel/air mixture to undergo a swirling motion at the time of ignition. One such burner apparatus is disclosed in U.S. Pat. No. 5,437,262, which describes a burner in which premixed gaseous fuel and air is directed into a combustion chamber, swirled, and then ignited in order to heat a cooking vessel by a combination of conductive and radiative heat transfer.
More recently, burners of the so-called “internal flame” type have been developed in which the flames converge towards a central point. See for example U.S. Pat. No. 7,083,123, which describes a laterally mountable internal flame burner that includes a venturi tube to help provide sufficient air for combustion.
However, while these types of burners provide increased burner capabilities in terms of dynamic power range, energy efficiency, and heat-loss reduction, there remains room for improvement of burner design in terms of burner performance, as well as other aspects such as convenience of use and resistance to spillage.